Hello and welcome to the community!
First of all there is no Veeamone 4a, latest version is v9.5 u4.
I have checked the report (I guess we are talking about VMWARE CUSTOM PERFORMANCE) and it works fine with the mentioned parameters.
Do you have an open support case for that issue?
Thanks!

I experience the same issue. After upgrading to VeeamOne 9.5 Update 4 I 'lost' almost all off my configured reports. Lost in the sense of that I have to redo all the selection criteria, so basically rebuilding all the reports. That would be okay, kind of, but I also run into the fact that I can't select any objects in the reports. I can select them but the selection won't get applied. The error message I get back from the scheduled report job (in Session Statistics) is the following: "Report parameter Object type is empty".

Looks like you have 2 issues: first is that upgrade removed your reports and second is that parameters can not be selected.
Both issues are not known. Please contact support team and let us know the case number.
Thanks!

After contacting support we decided to restart with a fresh database and recreated the reports from scratch. Support offered to check the DB. We didn't choose for that route and decided to start with a fresh DB. Loosing the VeeamOne history wasn't a big deal for us.